Drafting triangle



DRAFT ING .TRIANGLE Fil d April 14, 1957 5 FIGIl C INVENTOR EL RWCOFFEYATTORNEY Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to drafting triangles, such as are used veryextensively by draftsmen for making drawings.

In accordance with usual present practice, the

\g equipment of a draftsman consists of at least two trianglesa 45 and a30 x 60 triangleand a protractor for laying out angles other than thoseof said triangles.

Objects of the present invention are:

m 1. To provide a single triangle which will provide all the services ofthe usual two triangles; and

2. To provide a protractor scale on the external, diagonal edge of myimproved triangle where it 5 will be readily available for laying outangles other than those which the triangle itself provides.

The invention also comprises the various other features and details ofconstruction, hereinafter described and claimed.

20 In the accompanying drawing, in which a triangle embodying myinvention and improvements is fully illustrated,

Fig. 1 is a plan view, on a relatively large scale, of a triangleembodying my invention and im- 5 provements without a protractor scale;and

Fig. 2 is a view on a relatively small scale, of the triangle shown inFig. 1, formed on which is a protractor scale, arranged in accordancewith my invention, to effect the objects thereof.

30 Describing the invention with reference to the drawing and referringin the first instance, to Fig. 1, my improved trianglewhich may be madeof Celluloid or other suitable material, has two edges, A-B and BC,which are perpendicular to each 35 other and of different lengths, and adiagonal edge, which connects the remote ends of the perpendicular edgesof the triangle, said diagonal edge comprising only two sections, one ofwhich extends at an angle of 30 to the longer perpen- 40 dicular edge ofthe triangle, and the other at an angle of 45 to the shorterperpendicular edge (01. tie-104) thereof-said sections forming are-entrant angle and meeting each other at an angle of 195.

Preferably, but not necessarily, the triangle will be cut out as shownat E.

Excepting that the triangle shown in Fig. 2 is 5 provided with aprotractor scale formed only on its external, diagonal edge, theforegoing description of the triangle, shown in Fig. 1, will applyequally to the triangle shown in Fig. 2 and the same and correspondingparts are therefore, designated by the same reference characters in bothfigures.

As shown in Fig. 2, the center point, to which the graduations of theprotractor scale are referred, is positioned at the juncture of theperpendicular edges of the triangle, and the graduations thereof areformed on the external, diagonal edge of the triangle, opposite the apexof the angle formed by its perpendicular edges.

While I have illustrated and described the preferred form andarrangement of parts for carrying the invention into effect, this iscapable of Variation and modification, without departing from the spiritof the invention. I therefore do not wish to be limited to the detailsherein shown and described, but desire to avail myself of suchvariations and modifications as fall within the scope of the appendedclaim.

I claim:-

A drafting triangle having external meeting edges, which are ofdiiferent lengths and perpendicular to each other, and an external,diagonal, third edge which connects the ends of said perpendicular edgesremote from their meeting point, said third edge comprising only twosections, one of which extends at an angle of 30 to the longer of saidperpendicular edges, and the other at an angle of to the shorter of saidperpendicular edges, said sections meeting to form a re-entrant angle of40 ELMER W. COFFEY.

